Biomass, in particular biomass of plant origin, is recognized as an abundant potential source of fuels and specialty chemicals. See, for example, “Energy Production from Biomass” by P. McKendry, Bioresource Technology, vol. 83 (2002), pp. 37-46 and “Coordinated Development of Leading Biomass Pretreatment Technologies” by Wyman et al., Bioresource Technology, vol. 96 (2005), pp. 1959-1966. Refined biomass feedstock, such as vegetable oils, starches, and sugars, can be substantially converted to liquid fuels including biodiesel (e.g., methyl or ethyl esters of fatty acids) and ethanol. However, using refined biomass feedstock for fuels and specialty chemicals can divert food sources from animal and human consumption, raising financial and ethical issues.
Alternatively, inedible biomass or biomass grown on media that cannot support the growth of foodstuff (e.g., salt water, waste water) can be used to produce liquid fuels and specialty chemicals. For example, aquacultural biomass (e.g., micro and/or macro algae, which can grow in salt water and/or waste water) are potential feedstocks for producing fuels and specialty chemicals. Accordingly, aquacultural biomass can supplement and/or replace other source of inedible biomass such as agricultural waste (such as bagasse, straw, corn stover, corn husks, and the like), specifically grown energy crops (like switch grass and saw grass), and other sources such as trees, forestry waste (e.g., wood chips and saw dust from logging operations), paper waste, or paper mill waste.
Algae can be grown or cultivated commercially for food, vegetable oils, and other industrial products (e.g., agar). However, not all algae presently have commercial value. Algae include micro algae and macro algae. Micro algae are microscopic photosynthetic organisms, and include over 20,000 species of unicellular organisms that exist individually or in groups. Depending on the species, micro algae size can range from micrometers to hundreds of micrometers. Some micro algae can produce significant amounts of natural oils (e.g., triglycerides), which can be processed into biofuel (e.g., fatty acid alcohol esters) and unsaturated fatty acids (e.g., omega-3 fatty acids). Macro algae, more commonly known as seaweed, can grow to considerable size (e.g., 10-100 m). Macro algae are macroscopic, multicellular algae and include some members of the red, brown, and green algaes. Macro algae can be cultivated as a food source, as well as for the extraction of gelatinous substances such as alginate, agar, and carrageenan.
Oil from algae can be converted into a bio-fuel. For example, conversion of algae biomass can proceed through separation of oil from cellulosic components and conversion of the oil into a fuel such as biodiesel. Separation can reduce product yield because oil can be lost to the cellulosic component. Separation can reduce product yield because the cellulosic component must be discarded (e.g., only a fraction of the biomass is converted) or separately converted (e.g., conventional methods generally require different conditions for converting triglycerides and cellulosic component).